A vacuum filler is a machine used for filling pasty products. The pasty products are moved with the aid of a vane cell feed system under a vacuum.
Objective
Levelling the weight of pre-packaged goods in the food sector, especially those involving viscous or pasty products, places extremely high demands on the reproducible accuracy of filling and portioning systems. In order to achieve this, technical and technological issues as well as product-specific characteristics have to be taken into account. In addition to the aforementioned factors, the requirements on the quality of an end product is a key issue when selecting or implementing a technical process solution. The development of vacuum filling machines has made it possible to fulfill both the technical and the quality-related requirements.
In the food sector, moving or transporting fluids is achieved with the aid of pump technology. Colloquially, this is known as filling or portioning. Various different types of pumps are used, depending on the type of filling products to be moved. Vacuum fillers with vane cell feed systems and vacuum feeding are commonly used for viscous products. The products are transported with the aid of a hopper with a feeding device, a vane cell feed system under a vacuum and appropriate volume expulsion in the pump housing. This is basically a volumetric feed principle, which means that a certain weight is defined via a volume. In addition to the vane cell feed systems, also known as rotary vane pumps, there are also screw feed systems with feed augers, toothed wheel feed systems and evacuated lifting cylinders. With all these systems, transportation is achieved via volume expulsion under a vacuum. Vacuum fillers are traditionally used in the meat processing industry as well as in other food sectors. They can also be found in some non-food sectors. Generally speaking, vacuum fillers can be used for filling pasty and compressible products.
History
The first vacuum filler was developed in the early 1960s. The technology has been refined since then.
Requirements/effects
The pumpability of viscous or pasty products has a key effect on the reliable function of a vacuum filler. Filling products in the food sector can be characterised with the aid of various different properties related to their pumpability (“fillability”). They are either physical characteristics that can be measured directly or they are sensory attributes.
Gas content/density The gas content is also called the “air content”. The air content of a fluid is the percentage share of air that enters the fluid during grinding/mixing processes. This can be measured using special apparatus and has a direct relationship to the density of a fluid. Compressibility The compressibility depends on the air content of a fluid. A high level of compressibility is linked to a high gas content in the fluid. Viscosity Viscosity is a measure of the consistency of a fluid. The higher the viscosity, the higher the consistency of the fluid is (it is less fluid); the lower the viscosity, the lower the consistency of it is (more fluid). Highly-viscous filling products in the food processing industry are primarily found in the meat, bakery products and convenience food sectors. These highly-viscous substances are commonly referred to as being “pasty”. The fluidity is the basic requirement for the pumpability of a fluid. The viscosity can also be determined using suitable rheological measuring apparatus. In the food sector, the viscosity is primarily dependent on the fluid content of the filling product. Temperature The temperature is a key factor for pumpability as it has a direct effect on the viscosity as well as on the product quality. Texture, fibrousness, dimensions of the inserts Specific sensory characteristics of a filling product have a significant effect on the assessment of the fillability and compliance with the precise weight. Weight accuracy With the help of modern filling technology in the food sector, accurate portioning with a difference of up to 1% in relation to the required volume of a portion can be achieved.